41529-93-5Relevant academic research and scientific papers
Ligand effects on heats of protonation of multihydrido-transition metal complexes of osmium and iridium
Rottink, Mary K.,Angelici, Robert J.
, p. 3282 - 3286 (2008/10/08)
Titration calorimetry has been used to determine heats of protonation (ΔHHM) of the metal in (H)2Os(PR3)4 (PR3 = PPhMe2, PPh2Me, PPh(OEt)2, P(OEt)3), (H)4Os(PR3)3 (PR3 = PPhMe2, PPh2Me), HIr(CO)(PPh3)3, and CpIr(ER3)(H)2 (ER3 = PPh3, AsPh3, P(OPh)3) complexes with CF3SO3H in 1,2-dichloroethane solvent at 25.0°C. For the (H)2Os(PR3)4 complexes, the basicity (-ΔHHM) increases from 34.2 to 43.3 kcal/mol in the order P(OEt)3 2 2Me 2. The basicity (-(ΔHHM) of the metal in (H)4Os(PR3)3 (PR3 = PPhMe2, PPh2Me) increases by ～15 kcal/mol when two hydride ligands are replaced by a PR3 ligand to give (H)2Os(PR3)4. Replacement of the two hydride ligands in CpIr(PPh3)(H)2 by a CO ligand to give CpIr(PPh3)(CO) results in a 10.4 kcal/mol increase in the basicity (-(ΔHHM) of the metal. The basicities of the CpIr(ER3)(H)2 complexes increase in the order P(OPh)3 ? AsPh3 ≈ PPh3. Comparisons of the basicities of CpIr(PPh3)(CO) and (PPh3)2(H)Ir(PPh3)(CO) complexes show that replacement of Cp by the isoelectronic (PR3)2(H) ligand set increases the basicity of the metal. In other complexes, the replacement of Cp* by (PR3)2(H) also increases the metal basicity, but the effect varies greatly.
Complexes of the Platinum Metals. Part 32. Synthesis and Chemistry of some Iridium Sulphonate Derivatives
Harding, Alexander P.,Robinson, Stephen D.
, p. 947 - 952 (2007/10/02)
Sulphonic acids RSO3H (R = CF3, CH3, or C6H4CH3-p) react with mer-, , and to afford the products , , and respectively.Under more vigorous conditions the last reaction yields the bis(sulphonate) complexes .Thelability of the monodentate sulphonate ligands has been demonstrated by the substitution reactions of with a variety of neutral donor ligands.Products readily obtained in this manner include , 2 = 2,2'-bipyridyl, 1,10-phenanthroline, ethylenediamine, or o-NH2-C6H4NH2>, and trans-.Carbonylation of affords the tricarbonyl salt whereas under similar conditions the precursors (R = CH3 or C6H4CH3-p) yield the dihydride salts .Many of the complexes isolated were solvated by H-bonded molecules of sulphonic acids.Stereochemical assignments based on 1H, 19F, and 31 n.m.r. data are given for all the new products reported.
